Antioxidant, Antibacterial and Antibiofilm Activity of Nanoemulsion-Based Natural Compound Delivery Systems Compared with Non-Nanoemulsified Versions

Preparation and characterization of nano-emulsion formulations of Asparagus densiflorus root and aerial parts extracts: evaluation of in-vitro antibacterial and anticancer activities of nano-emulsion versus pure plant extract

OBJECTIVE

Preparation and characterization of nano-emulsion formulations for Asparagus densiflorus aerial and root parts extracts.

SIGNIFICANCE

Genus Asparagus is known for its antimicrobial and anticancer activities, however, freeze dried powder of aqueous - alcoholic extract prepared in this study, exhibited a limited water solubility, limiting its therapeutic application. Thus, encapsulation of its phytochemicals into nano-emulsion is proposed as a solution to improve water solubility, and facilitate its clinical translation.

METHODS

the composition of extracts for both aerial and root parts of Asparagus densiflorus was identified by HPLC and LC-MS analysis. Nano-emulsion was prepared via homogenization where a mixture of Castor oil: phosphate buffered saline (10 mM, pH 7.4): Tween 80: PEG 600 in a ratio of 10: 5: 2.5: 2.5, respectively. Nano-emulsion formulations were characterized for particle size, polydispersity index (PDI), zeta potential, TEM, viscosity and pH. Then, the antibacterial and anticancer activities of nano-emulsion formulations versus their pure plant counterparts was assessed.

RESULTS

The analysis of extracts identified several flavonoids, phenolics, and saponins which were reported to have antimicrobial and anticancer activities. Nano-emulsion formulations were monodispersed with droplet sizes ranging from 80.27 ± 2.05 to 111.16 ± 1.97 nm, and polydispersity index ≤0.3. Nano-emulsion formulations enhanced significantly the antibacterial (multidrug resistant bacteria causing skin and dental soft tissues infections) and anticancer (HuH7, HEPG2, H460 and HCT116) activities compared to their pure plant extract counterparts.

CONCLUSION

Employing a nano-delivery system as a carrier for phytochemicals might be an effective strategy to enhance their pharmacological activity, overcome their limitations, and ultimately increase their potential for clinical applications.

Eugenol and Aloe vera blended natural wax-based coating for preserving postharvest quality of Kaji lemon (Citrus jambhiri)

Edible coatings on fruits and vegetables preserve postharvest quality by reducing water loss and lowering respiration, and metabolic activities. The primary objectives of this study were to develop composite coating formulations using natural waxes (carnauba and shellac wax), eugenol nanoemulsion, and Aloe vera gel, and assess the potential impacts of the coating formulations on the postharvest quality and shelf-life of the Kaji lemon. The results show that eugenol nanoemulsion and Aloe vera gel enhanced the physico-chemical, antimicrobial and antioxidant properties of the developed coating. Notably, the fruits coated with optimized nanocomposite of wax with eugenol and aloe vera gel inclusion (SW + CW/EuNE-20/AVG-2) showed the lowest weight loss (16.56%), while the coatings of wax with only aloe vera gel (SW + CW/AVG-2) exhibited the highest firmness (48 N), in contrast to the control fruit, which had 27.33% weight loss and 9.6 N firmness after 28 days of storage, respectively.

Ultrasound-Assisted Nanoemulsion Loaded with Optimized Antibacterial Essential Oil Blend: A New Approach against Escherichia coli, Staphylococcus aureus, and Salmonella Enteritidis in Trout (Oncorhynchus mykiss) Fillets

This study aimed to obtain and characterize an oil-in-water nanoemulsion (NE) loaded with an in vitro optimized bactericidal essential oil blend of 50% oregano, 40% thyme, and 10% lemongrass and to evaluate its potential at three different concentrations (0.5%, 1%, and 2%) in the inactivation of Escherichia coli, Staphylococcus aureus, and Salmonella enterica serotype Enteritidis inoculated in rainbow trout fillets stored at 4 °C for 9 days. Regarding the NE, the nanometric size (<100 nm) with low polydispersion (0.17 ± 0.02) was successfully obtained through ultrasound at 2.09 W/cm2. Considering the three concentrations used, S. Enteritidis was the most susceptible. On the other hand, comparing the concentrations used, the NE at 2% showed better activity, reducing S. Enteritidis, E. coli, and S. aureus by 0.33, 0.20, and 0.73 log CFU/g, respectively, in the trout fillets. Thus, this data indicates that this is a promising eco-friendly alternative to produce safe fish for consumption and reduce public health risks.

Application of Nanoparticles in Human Nutrition: A Review

Nanotechnology in human nutrition represents an innovative advance in increasing the bioavailability and efficiency of bioactive compounds. This work delves into the multifaceted dietary contributions of nanoparticles (NPs) and their utilization for improving nutrient absorption and ensuring food safety. NPs exhibit exceptional solubility, a significant surface-to-volume ratio, and diameters ranging from 1 to 100 nm, rendering them invaluable for applications such as tissue engineering and drug delivery, as well as elevating food quality. The encapsulation of vitamins, minerals, and antioxidants within NPs introduces an innovative approach to counteract nutritional instabilities and low solubility, promoting human health. Nanoencapsulation methods have included the production of nanocomposites, nanofibers, and nanoemulsions to benefit the delivery of bioactive food compounds. Nutrition-based nanotechnology and nanoceuticals are examined for their economic viability and potential to increase nutrient absorption. Although the advancement of nanotechnology in food demonstrates promising results, some limitations and concerns related to safety and regulation need to be widely discussed in future research. Thus, the potential of nanotechnology could open new paths for applications and significant advances in food, benefiting human nutrition.

Carvacrol Microemulsion vs. Nanoemulsion as Novel Pork Minced Meat Active Coatings

Carvacrol is well documented for its antibacterial and antioxidant effects. However, its high volatility has directed researchers toward nanoencapsulation technology according to bioeconomy and sustainability trends. This study examined and compared free carvacrol (FC), carvacrol microemulsion (MC), carvacrol microemulsion busted with chitosan (MMC), and carvacrol nanoemulsions (NC) as active coatings on extending minced pork meat shelf life at 4 ± 1 °C for 9 days, focusing on microbiological, physiochemical, and sensory characteristics. The research involved pre-characterizing droplet sizes, evaluating antioxidants, and determining antibacterial efficacy. The results demonstrated that NC with a 21 nm droplet size exhibited the highest antioxidant and antibacterial activity. All coatings succeeded in extending the preservation of fresh minced pork meat in comparison to the free carvacrol sample (FC). The NC coating showed the highest extension of minced pork meat preservation and maintained meat freshness for 9 days, with a lower TBARs of 0.736 mg MDA/Kg, and effectively reduced mesophilic, lactic acid, and psychotrophic bacterial counts more significantly by 1.2, 2, and 1.3 log, respectively, as compared to FC. Sensory assessments confirmed the acceptability of NC and MCC coatings. Overall, the carvacrol-based nanoemulsion can be considered a novel antioxidant and antimicrobial active coating due to its demonstrated higher efficacy in all the examined tests performed.

Carvacrol Treatment Reduces Decay and Maintains the Postharvest Quality of Red Grape Fruits (Vitis vinifera L.) Inoculated with Alternaria alternata

In this study, we isolated and identified pathogenic fungi from the naturally occurring fruits of red grapes, studied their biological characteristics, screened fifteen essential oil components to find the best natural antibacterial agent with the strongest inhibitory effect, and then compared the incidence of postharvest diseases and storage potential of red grapes treated with two concentrations (0.5 EC50/EC50) of essential oil components (inoculated with pathogenic fungi) during storage for 12 d at room temperature. In our research, Alternaria alternata was the primary pathogenic fungus of red grapes. Specifically, red grapes became infected which caused diseases, regardless of whether they were inoculated with Alternaria alternata in an injured or uninjured state. Our findings demonstrated that the following conditions were ideal for Alternaria alternata mycelial development and spore germination: BSA medium, D-maltose, ammonium nitrate, 28 °C, pH 6, and exposure to light. For the best Alternaria alternata spore production, OA medium, mannitol, urea, 34 °C, pH 9, and dark conditions were advised. Furthermore, with an EC50 value of 36.71 μg/mL, carvacrol demonstrated the highest inhibitory impact on Alternaria alternata among the 15 components of essential oils. In the meantime, treatment with EC50 concentration of carvacrol was found to be more effective than 0.5 EC50 concentration for controlling Alternaria alternata-induced decay disease of red grapes. The fruits exhibited remarkable improvements in the activity of defense-related enzymes, preservation of the greatest hardness and total soluble solids content, reduction in membrane lipid peroxidation in the peel, and preservation of the structural integrity of peel cells. Consequently, carvacrol was able to prevent the Alternaria alternata infestation disease that affects red grapes, and its EC50 concentration produced the greatest outcomes.

Recent Trends in Active Packaging Using Nanotechnology to Inhibit Oxidation and Microbiological Growth in Muscle Foods

Muscle foods are highly perishable products that require the use of additives to inhibit lipid and protein oxidation and/or the growth of spoilage and pathogenic microorganisms. The reduction or replacement of additives used in the food industry is a current trend that requires the support of active-packaging technology to overcome novel challenges in muscle-food preservation. Several nano-sized active substances incorporated in the polymeric matrix of muscle-food packaging were discussed (nanocarriers and nanoparticles of essential oils, metal oxide, extracts, enzymes, bioactive peptides, surfactants, and bacteriophages). In addition, the extension of the shelf life and the inhibitory effects of oxidation and microbial growth obtained during storage were also extensively revised. The use of active packaging in muscle foods to inhibit oxidation and microbial growth is an alternative in the development of clean-label meat and meat products. Although the studies presented serve as a basis for future research, it is important to emphasize the importance of carrying out detailed studies of the possible migration of potentially toxic additives, incorporated in active packaging developed for muscle foods under different storage conditions.